Composition of paraffin wax and a hydrogenated polymer oil



United States Patent() COMPOSITION OF PARAFFIN WAX AND A HYDROGENATEDPGLYMER OIL David Young, Westfield, and Delmer L. Cottle, HighlandPark,N. J., assignors to Esso Research and Enginearing Company, a corporationof Delaware No Drawing. Original application May 27, 1954, Serial No.432,936. Divided and this application February 1, 1955, Serial No.485,618

2 Claims. (Cl. 106-271) It is known to prepare oily polymers by thepolymerizatron of a conjugated diolefin such as butadiene or thecopolymerization of such a diolefin with a vinyl aromatic such asstyrene. These polymeric oils have been found to be excellent dryingoils and therefore useful in preparing varnishes, paints and enamels.

However, the films prepared from theseoils have been found prone tocheck or fracture badly on exterior exposure and finally to flake awayfrom the supporting surface. Furthermore, baked films prepared fromthese oils,

while superior to most synthetic drying oils, still are not assatisfactory as those obtained from most natural drying oils.

According to the present invention such polymer oils are subjected tohydrogenation to improve the weather resistance and adhesion of thebaked films and other properties of the oil and to obtain productssuitable as plasticizers for natural and synthetic rubber, polyethylene,asphalt and wax and as addition agents for lubricating oils and thelike. 1 t

The polymer oil which is to be subjected to hydrogenation, according tothis invention, is prepared by polymerizing about 50 to 100 parts ofbutadiene-1,3 and about 50 to parts of styrene at 25 to 105 C. in thepresence of 1.2 to 8 parts of finely divided sodium, per 100 parts ofmonomers, as the catalyst and of about 50 to 500 parts of an inerthydrocarbon diluent boiling between 0 and 250 C., preferably between 20and 200 C., in either a batch or continuous process in accordance withthe disclosures of U. S. Patents 2,795,631 filed July 2, 1954; 2,712,562filed March 5, 1954; and Example III of 2,709,662 filed July 16, 1948.

The object of this invention is a composition of parafiin wax and ahydrogenated polymer oil.

The above choice of monomers is quite specific as halogen-containingmonomers such as chloroprene or chlorinated styrene are not suited forpolymerization in the presence of sodium. Higher homologues ofbutadiene, i. e. piperylene, isoprene, and dimethylbutadiene aresuitable for the purposes of the present invention. The replacement ofstyrene by its ring alkylated homologues, such as para-methyl styrene,meta-methyl styrene, dimethyl styrene and the corresponding ethylsubstituted homologues is. the only variation of monomers permissibleherein; however, styrene is the most practical from the economicstandpoint. Alpha methyl styrene is unsuitable because it is toounreactive toward sodium.

Materials used as diluents in the polymerization should be liquid at thepolymerization temperature, that is, they should boil between 20 and 250C., although more volatile materials boiling as low as -l C., may alsobe used, providing that the polymerization pressure is 1 increasedcorerspondingly. Preferred diluents are esseneliect on thepolymerization rate.

(3.), but butane, pentane, benzene, toluene, xylene, cycle-g vexcessively that their use is impractical.

hexane, butenes, pentenes'or similar inert hydrocarbons are also usable,individually or in admixture with each other. In general, the aromaticsolvents are not so desirable as the aliphatic ones because of thetoxicity of the former. The hydrocarbon diluents are used in amountsranging from 50 to 300 parts by wt. per parts of monomers.

An important feature of the process involves the use of a substantialamount of certain C to C aliphatic ethers as codiluents or modifiersalong with the hydrocarbon diluent described above. A particularlyoutstanding promoter for the batch process has been found in dioxane-l,4whose presence in the feed aids in the production of a colorless productof desirable viscosity and good drying properties, and promotes thereaction sufficiently to give 100% conversoin at 50 C., in a period ofabout 612 hours. Similarly favorable results were also obtained withdiethyl ether (C H O, as well as with methylal, ethylal, methyl acetal,and tertiary butyl methyl ether. In the batch process, diethyl ether isusable, although the initial induction period tends at timesto besomewhat long. However, diethylether is the preferred ether in acontinuous process as the difliculty in starting upthe reaction occursonly at the beginning of the polymerization which runs for a long periodof time in contrast to batching runs which have to be started upfrequently. Diethyl ether is less subject to undesirable side reactionswith metallic sodium, and it is a more vigorous promoter than dioxane.However, dioxane is usable also, but not preferred. Other ethers usefulto a still lesser extent are diethyl acetal, vinyl isobutyl ether,dihydropyrane and ethylal, all of which have a favorable effect onimproving the color of the product.

In contrast to the preferred ethers named earlier herein, the fourethers just named have a moderate retarding Finally, all cyclic ethershaving an OCO group in a ring structure, such as dioxane-1,3, dioxolane,paraldehyde and glycol ethylidene diacetal, inhibit the polymerizationrate so Dimethyl ether also does not serve the desired purpose, both asregards reaction rate and product quality. Thus the cyclic ethers musthave the oxygen atoms separated by at least two carbon atoms. a

The ether promoter is used in amounts ranging from about 1 to 100 parts,preferably 5 to 50 parts, by wt. per 100 parts of monomers. In selectingthe ether co-diluent it is especially desirable in many cases to selectan ether having a boiling point of at least 10 C. below the lower limitof the boiling range of the hydrocarbon diluent, and thus, when using amineral spirits having a boiling range of 150 C. to 200 C., etherco-diluents boiling between about 25 and C., are preferred for thereason that their separation from the hydrocarbon diluent in thepolymerized reaction mixture is greatly facilitated by virtue of thestated difference in boiling points. If the polymer is recovered inabout 100% purity, the ether may conveniently boil in the range of thehydrocarbon diluent since both may be recycled together in making up thefresh feed to the reactor.

- It is also advantageous to use about 10 to 50%, preferably 10 to 30weight percent (based on sodium) of an alcohol in the polymerizationrecipe. Suitable alcohols include isopropanol, isobutanol, isopentanol,secondary butanol, and tertiary butanol. The coarser the catalystdispersion, the more essential it is to have a sufficient amount ofalcohol promoter present.

The reaction time and induction period vary depending on the degree ofcatalyst dispersion, reaction tempera- 3 ture, purity of feed materialsand sequence of monomer addition.

The catalyst is usually fed to the reactor as a slurry of metalparticles dispersed in 2 to 200 parts by weight of a hydrocarbon liquid,which may or may not be the same as the reaction diluent. Agitation ofthe reaction mixture during synthesis increases the efiiciency of thecat alyst.

Destruction of catalyst at the end of the reaction is effectivelyaccomplished by adding to the reaction mixture a moderate excess of ananhydrous C to C fatty acid which is soluble in the hydrocarbon mixture,e. g. formic, acetic or pentanoic, or with sulfuric acid as described incopending application Serial No. 396,324, filed December 4, 1953, PatentNo. 2,712,561. After destruction of the catalyst the crudepolymerization product containing the salts, excess acid and otherimpurities is neutralized with ammonia, and the neutralized product isfinally filtered preferably with a filter aid such as silica gel, clay,charcoal or its equivalent. Separation can also be accomplished bycentrifuging, if desired. Other ways of destroying the catalyst may beused, such as by adding alcohol, or inorganic acids.

Since the resulting polymer solution is usually too dilute for mostpractical use as a varnish or enamel base, it is advantageous to distilloff some of the volatile hydrocarbon solvent until -a product containingnot less than 40% to 70% non-volatile matter is obtained, thenonvolatile matter being the polymeric drying oil. Where even morehighly concentrated products are desired it is possible to raise theconcentration of the polymeric drying oil to as much as 99% or greaternon-volatile matter by still more extensive distillation or stripping;the use of a stripping gas, such as methane or a mixture of lighthydrocarbons, is advantageous where highly concentrated drying oils aredesired. Alternatively, one may use a low boiling diluent such asbutane, a pentane, or a low boiling naphtha in the synthesis step andthus simplify the eventual removal of the diluent from the polymericproduct.

The product of the present invention is usually a solution of polymericdrying oil in a suitable hydrocarbon solvent such as solvent naphtha ormineral spirits and is, depending on the amount and type of other used,a clear, colorless to light yellow varnish composition, the polymercontent of which has a viscosity of about 0.15 to 22 poises at 50% N. V.M. and preferably 0.15 to 3.0 poises at 50% N. V. M.

If desired, the product viscosity can be readily increased within orabove the limits given above by heatbodying the polymer, preferably in50 to 75% concentration, in the absence of air at temperatures between200 and 300 C., e. g. at 220 to 260 C. The clear varnish composition canbe brushed, poured or sprayed and gives good clear films on drying inair or baking, especially when conventional driers such as naphthenatesor octoates of cobalt, lead or manganese are added thereto. Excellentfilms can be prepared by baking, even in the absence of driers.

Furthermore, when the drying oil compositions of the present inventionare intended for use in pigmented enamels, their gloss and wetting powercan be further improved by reacting them with a small amount of a polarcompound such as maleic anhydride, acrylonitrile, thioglycollic acid orother equivalent materials described in copending applications Ser. Nos.102.703, filed July 16, 1949 (now issued as Patent No. 2,652,342), and106,487, filed July 23, 1949 (now issued as Patent No. 2,683,162).

Lead driers can be used also, but, unlike in the case of natural dryingoil varnishes, are not necessary here. This, of course, is a decidedadvantage in some cases in view of the toxicity of the lead driers.

Another important advantage of the invention is that the present dryingoils can be used as a varnish without the addition of any extraneouspolymer or resin thereto.

4 This further distinguishes the products of the invention from priorart drying oils, notably the natural oils such as linseed, which requirethe addition of rosin, ester gum or a phenolic resin thereto when avarnish is desired.

Now, according to the present invention, a polymer oil made as describedabove is subjected to hydrogenation to reduce its color and iodinenumber and effect other improvements. This hydrogenation may be carriedout either by treating the polymer before stripping out part or all ofthe diluent hydrocarbons or the stripped polymer. may be redissolved ina suitable inert solvent to facilitate hydrogenation in the liquidphase.

The hydrogenation may be carried out under any desired hydrogenatingconditions, such as contacting the polymer solution with gaseoushydrogen under a pressure of about to 5000 p. s. i. g., preferably about500 to 3000 p. s. i. g., at a temperature range from about 200 to 500F., preferably about 300 to 450 F., for a time ranging from a fewminutes to several days, but preferably about 10 to 30 hours. In orderto avoid gel formation by crosslinking, it is necessary that thehydrogenation be carried out gradually as instantaneous hydrogenationresults in the production of an insoluble product. It is preferred touse a hydrogenation catalyst, which may be any of the known types suchas nickel, reduced nickel, platinum, or various metal sulfides, etc.,either alone or supported on a suitable carrier of great porosity orsurface area, e. g. charcoal, silica gel, etc. In batch operation, theamount of catalyst should generally be about 5 to 5 0% by wt. based onthe weight of polymer subjected to hydrogenation. In continuoushydrogenation, the feed rate of the polymer or the polymer solutionthrough the catalyst bed should be about 0.1 to 5, preferably 0.3 to 1.0v./v./hr.

After the hydrogenation is completed, i. e. carried out to the desiredpressure drop or reduction in iodine number, and improvement in color orother characteristics, the solution may be subjected to flashing ordistillation to remove the solvent and any other volatile materials, andif desired, the hydrogenated polymer may be stored, shipped, orotherwise marketed for use while still dissolved in the hydrogenationsolvent. In such a case, however, it should be subjected to filtering orother purification treatment to remove the catalyst.

These hydrogenated polymers have iodine numbers between 1 and and havevalue as varnish extenders, for cobodying with other resins and/ordrying oils, for floor tile compositions, printing inks, paints, asbonding agents for plywood, as plasticizers for natural rubber andsynthetic rubbers, such as butyl rubber, GR-S, GR-N, asphalt,polyethylene and wax, and as addition agents for lubricating oils andthe like. The proportions may vary between 1 and 30% of the hydrogenatedoil.

The hydrogenated copolymers as described above have been found to havelubricating oil and wax modifying characteristics which make themparticularly desirable for blending with various lubricating oil basestocks and waxes. It has been found that either natural occurringmineral oils or synthetic lubricating oils may be improved by theaddition of minor but improving proportions of the hydrogenated polymersdescribed above.

It has also been found that the residual unsaturation present in thehydrogenated polymeric materials make it possible to further react thehydrogenated polymeric material with agents such as sulfides ofphosphorus, chlorinated aliphatic compounds, acylating agents,sulfonating agents and the like. These reaction products also enchancethe desirable characteristics of lubricating oils and waxes with whichthey are blended.

The objects, advantages, and details of the invention will be betterunderstood from the following experimental data which are given for thesake of illustration, but without intending that the invention belimited specifically thereby.

Example I An oily copolymer of butadiene and styrene was preparedaccording to the following recipe:

Parts by wt. Butadiene 80 Styrene 20 Varsol Naphtha 190 Dioxane 30Sodium 1.5 Isopropanol 0.3

Temperature, 40 C.

Complete conversion was obtained in 10 hours. The catalyst was destroyedand removed. The product was finished to 90% N. V. M. as described aboveand had a viscosity of 1.0 poise at 50% N. V. M.

Example II Example III The copolymer of Example I above was hydrogenatedin heptane solution at 250 C. at 2400 to 3000 lbs. hydrogen pressure.The resulting material had an ASTM Y iodine number of 18.

This hydrogenated copolymer was blended in a paraffin wax and standardwax inspection evaluations carried out. Results are set out below.

ASTM Percent Hydrogenated Oopolymer M. 1%., Vise. at Penetra- F. 260tion This application is a division of Serial No. 432,936, filed May 27,1954.

The nature of the present invention having been thus fully set forth andspecific examples of the same given, what is claimed as new and usefuland desired to be secured by Letters Patent is:

1. A composition of matter consisting essentially of p-araifin wax and lto 20% of a hydrogenated liquid polymer oil having an iodine numberbelow 150 and prepared by mixing to parts by weight of butadiene-1,3with 50 to 0 parts by weight of styrene, 50 to 500 parts by weight of aninert hydrocarbon diluent boiling between about 0 and 250 C., 1 to 100parts of an ether selected from the group consisting of C -C aliphaticethers and cyclic ethers having the oxygen atoms separated by 2 carbonatoms, 1.2 to 8 parts of finely dispersed sodium and 10 to 50% by weightof a C -C alcohol based on the weight of sodium, heating the mixture toa reaction temperature between 25 and C. until substantially 100%conversion is obtained, destorying and removing the catalyst andsubsequently contacting the resulting polymer with hydrogen under thepressure of about 100 to 5000 p. s. i. g. at a temperature between about200 and 500 F. in the presence of a hydrogenation catalyst.

2. A composition according to claim 1 in which 80 parts by weight ofbutadiene-1,3, 20 parts by weight of styrene, 200 parts by weight ofhydrocarbon diluent, 30 parts by weight of dioxane, 1 to 5 parts byweight of sodium and 0.3 part by weight of isopropyl alcohol are reactedat 40 C. to produce the liquid polymer oil which is submitted tohydrogenation at 25 C. under a pressure of 380 to 3000 p. s. i, g. inthe presence of a nickel catalyst.

References Cited in the file of this patent UNITED STATES PATENTS2,638,460 Crouch May 12, 1953 2,640,809 Nelson June 2, 1953 2,687,963Marshall Aug. 31, 1954 2,709,662 Koenecke May 31, 1955

1. A COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF PARAFFIN WAX AND 1TO 20% OF A HYDROGENATED LIQUID POLYMER OIL HAVING AN IODINE NUMBERBELOW 150 AND PREPARED BY MIXING 50 TO 100 PARTS BY WEIGHT OFBUTADIENE-1.3 WITH 50 TO 0 PARTS BY WEIGHT OF STYRENE, 50 TO 500 PARTSBY WEIGHT OF AN INERT HYDROCARBON DILUENT BOILING BETWEEN ABOUT 0 TO250*C., 1 TO 100 PARTS OF AN ETHER SELECTED FROM THE GROUP CONSISTING OFC4-C8 ALIPHATIC ETHERS AND CYCLIC ETHERS HAVING THE OXYGEN ATOMSSEPARATED BY 2 CARBON ATOMS 1.2 TO 8 PARTS OF FINELY DISPERSED SODIUMAND 10 TO 50% BY WEIGHT OF A C3-C5 ALCOHOL BASED ON THE WEIGHT OFSODIUM, HEATING THE MIXTURE TO A REACTION TEMPERATURE BETWEEN 25 TO105*C. UNTIL SUBSTANTIALLY 100% CONVERSION IS OBTAINED, DESTROYING ANDREMOVING THE CATALYST AND SUBSEQUENTLY CONTACTING THE RESULTING POLYMERWITH HYDROGEN UNDER THE PRESSURE OF ABOUT 100 TO 5000 P.S.I.G. AT ATEMPERATURE BETWEEN ABOUT 200 AND 500* F. IN THE PRESENCE OF AHYDROGENATION CATALYST.